The present invention relates to vehicular security systems. Even more particularly, the present invention relates to security systems for disabling electrical subsystems of a vehicle for preventing unauthorized activation. Moreover, the present invention relates to preventions of joyriding and the theft of automobiles which have resulted in substantial economic loss across this country.
Although a substantial number of anti-theft devices have been devised, xe2x80x9cprofessionalxe2x80x9d and even amateur thieves are adept at overriding such devices and xe2x80x9chot-wiringxe2x80x9d a vehicle for removal.
Attempts have been made to secure a vehicle by providing locks to the hood and doors of the vehicle making the interior of the vehicle difficult to access. Further attempts have been made to secure the interior of a vehicle by redesigning the window opening to prevent against the insertion of wire or door xe2x80x9cjimmiesxe2x80x9d for retracting the door lock. However, individuals intent on removing an automobile normally have little problem gaining access to the interior of the vehicle using an assortment of tools, including simply breaking the driver""s side window. Once access to the interior of the vehicle is obtained, the engine compartment can easily be accessed by actuation of the hood unlock lever enabling car thieves to hot-wire the engine.
Key actuated and combination type lock switches have been devised to prevent unauthorized activation of various electrical circuits, such as the ignition circuit, distributor system, power system and the like in motor vehicles to prevent theft. These locks include electrically coded keys, mechanically coded keys, digital entry keypads, electro-optically coded keys and radio frequency (RF) keys. Unfortunately, there are known methods for defeating each of these locking systems by bypassing the locking system such as by hot-wiring the locking system or by illegally capturing and rebroadcasting RF security codes.
Additional security systems have been directed to deactivating the starter solenoid, starter motor and/or the distributor. Electrical energy to the winding of a starter solenoid actuates a plunger which closes a circuit between the vehicle""s battery and the starter motor. The starter solenoid simultaneously actuates a shift lifter which forces a pinion gear into meshing engagement with the vehicle""s flywheel to thereby mechanically connect the starter motor to the engine during vehicle ignition. The starter motor is contained in a housing typically located beneath the internal combustion engine of a vehicle. The starter motor includes a rotatable armature which engages the vehicle""s flywheel. When current is supplied through the starter solenoid, the starter motor causes the armature to rotate, thereby rotating the vehicle flywheel causing the internal combustion engine to xe2x80x9cstartxe2x80x9d. Meanwhile, the distributor controls the firing sequence of the engine spark plugs to enable the engine to continue running.
Several attempts have been made to deactivate or disable each of these engine subsystems to prevent unauthorized movement of a vehicle. For example, U.S. Pat. No. 4,141,332 describes an encoder/decoder system for shorting the ignition key switch. U.S. Pat. No. 5,942,807 describes a theft deterrent system which includes a stopper for precluding engagement of the starter motor drive gear to the flywheel. Meanwhile, U.S. Pat. No. 4,733,638 describes a radio frequency transmitter/receiver system which requires activation prior to operating the vehicle""s starter motor.
U.S. Pat. No. 5,548,164 describes a security module which attaches to a vehicle""s starter solenoid. The security module includes an internal switch for interrupting power to the starter solenoid""s power terminal. Similarly, U.S. Pat. No. 6,026,773 describes an anti-theft system which is connected in series between a vehicle""s battery and the vehicle""s starter motor.
Unfortunately, all of the previous attempts to provide automotive security systems suffer from serious drawbacks. For example, many systems which impede activation of the electrical systems of a vehicle, such as the solenoid, starter or distributor, can be overcome by simple removal of the alarm system or by shorting the alarm system. Meanwhile, the system described in U.S. Pat. No. 4,733,638 requires an entirely new starter housing which would be difficult and expensive to construct, and would have to be built in numerous configurations to fit within a variety of vehicle engine housings. U.S. Pat. No. 5,548,164 describes a security system which attaches directly to the power terminal of a starter solenoid. To impede removal of the security module from the starter solenoid, additional housings are locked in place over the terminals of the starter solenoid to impede their access by unauthorized persons. Moreover, the systems described within U.S. Pat. Nos. 5,548,164 and 6,026,773 describe security systems which include switches which carry significant power between the battery and the power terminals of a starter solenoid. Unfortunately, the high power through such systems are susceptible to electrical noise, electric spikes and back EMF from the solenoid coil. In addition, heat from the power passing through the security system switch typically gives off significant heat which can damage the electronic components of the security system.
It is therefore an object of the present invention to provide a new and improved security system for vehicles.
It is a further object of the present invention to provide a vehicle security system which is both inexpensive and reliable.
It is still an additional object of the present invention to provide a vehicle security system which can be constructed to reside within the engine compartment of virtually all vehicles.
It is still an additional object of the present invention to provide a vehicle security system which can operate in connection with a variety of coding systems, such as key coding, RF coding, etc.
The present invention addresses the aforementioned disadvantages by providing an improved security system for impeding the unauthorized operation of a vehicle. The security system includes a security module which connects to one or more crucial electrical subsystems of the vehicle for disabling engine ignition or engine operation. Electrical subsystems include the vehicle solenoid, the starter motor, the battery and the distributor. The security module is connected in series with an electrical conductive path which connects any of these subsystems to the rest of the vehicle electrical system for selectively interrupting current along these electrically conducting paths for disabling the particular vehicle subsystem.
In a first embodiment of the invention, the security module is connected between the vehicle""s ignition switch and the initiate stud of the vehicle""s solenoid. In an alternative embodiment, the security module of the present invention is connected in series between the battery and ignition switch. Where the vehicle includes a solenoid and starter motor constructed as one unit, such as is installed in many Ford vehicles, the security module of the present invention is connected in series between a remote solenoid and the starter motor. The interruption of the current in any of these electrical paths will disable a vital subsystem of the vehicle making it virtually impossible to start the vehicle""s engine.
In accordance with the present invention, the security module attaches and locks directly to an electrical terminal of the vehicle subsystem which is intended to be disabled. To this end, the security module includes a housing having an opening at the bottom exterior of the housing which opens into a central bore. The bore is sized and configured for receipt of the electrical terminal of the vehicle subsystem for which it is intended to receive. Moreover, the security module includes a locking means for locking the housing to the electrical terminal of the vehicle subsystem so that once installed upon the electrical terminal, the security module cannot be removed without removal of the entire vehicle subsystem from the vehicle. In a preferred embodiment, the locking assembly includes one or more of jaws which are disposed within the housing""s central bore. The bore""s sidewalls are tapered so that the bore is more narrow towards its opening and widens upwardly towards the housing""s center. The locking means further includes a spring disposed within the housing""s bore for biasing the one or more jaws downwardly and inwardly towards the bore""s opening.
The security module is installed upon a vehicle subsystem""s electrical terminal simply by projecting the terminal upwardly and inwardly into the housing""s bore. Upon the electrical terminal engaging the locking assembly""s jaws, the jaws project upwardly and outwardly as the security module is forced downwardly upon the electrical terminal permitting the electrical terminal to project into the module""s bore. However, the security module cannot easily be removed from the electrical terminal as any force exerted upon the security module to remove the module from the electrical terminal will simply cause the jaws to be forced downwardly and inwardly towards the narrow region of the housing""s bore, thereby causing the jaws to grip the electrical terminal more tightly. Thus, once installed, the security module cannot be removed from a vehicle subsystem""s electrical terminal and the electrical terminal is covered and isolated by the security module""s housing to prohibit any physical or electrical access to the electrical terminal.
Located within the security module""s housing is a controller and a switching element which is connected in series between the jaws engaging the vehicle subsystem""s electrical terminal and the electrically conductive path along which current is intended to flow either to or from the electrical terminal. The controller may comprise a printed wiring board, digital code reader, micro controller, or the like for controlling the switching element from an open to a closed position upon receipt of enable or disable command for enabling and disabling the security system of the present invention. The enable and disable commands may be transmitted by a wireless RF transmitter which may be either affixed within the vehicle or carried by an authorized driver of the vehicle. In the alternative, the enable and disable commands may be transmitted by a activation module which is connected by wires or cable to the controller of the security module. The activation module is preferably mounted in the cabin of the vehicle, such as below the dashboard, and is activated by electrically coded keys, mechanically coded keys, digital entry keypads, electro-optically coded keys or radio frequency keys.
In a preferred embodiment of the invention, the security module of the present invention is affixed and locked directly to the initiator stud of the vehicle""s solenoid. The solenoid is connected in series to the vehicle""s ignition switch through the locking assembly""s jaws, the switching element and the electrically conductive path which, in this case, is the cable which would ordinarily be routed from the ignition switch directly to the initiate stud of the vehicle solenoid. Advantageously, by interrupting current to the initiate stud, the switching element does not encounter high current and thus less expensive switching elements can be employed. Moreover, the low current passing through the switching element is less prone to cause heat or electrical interference which can damage the security module""s controller.
The security system of the present invention provides for virtually universal application to all vehicles as the security module can be constructed to engage the initiate studs of a variety of different vehicle solenoids, and can even be constructed to engage the electrical terminals of a variety of different crucial vehicle electrical subsystems such as the vehicle""s battery or starter motor.
In addition, the security system of the present invention can be used in cooperation with virtually any type of known coding system such as mechanical key coding, RF coding, keypad coding, etc.
Other features and advantages of the present invention will be appreciated by those skilled in the art upon reading the detailed description which follows with reference to the attached drawings.